Btrfs: transaction handles everywhere

Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/transaction.h

@@ -0,0 +1,27 @@
+#ifndef __TRANSACTION__
+#define __TRANSACTION__
+
+struct btrfs_trans_handle {
+	u64 transid;
+	unsigned long blocks_reserved;
+	unsigned long blocks_used;
+};
+
+static inline struct btrfs_trans_handle *
+btrfs_start_transaction(struct btrfs_root *root, int num_blocks)
+{
+	struct btrfs_trans_handle *h = malloc(sizeof(*h));
+	h->transid = root->root_key.offset;
+	h->blocks_reserved = num_blocks;
+	h->blocks_used = 0;
+	return h;
+}
+
+static inline void btrfs_free_transaction(struct btrfs_root *root,
+					  struct btrfs_trans_handle *handle)
+{
+	memset(handle, 0, sizeof(*handle));
+	free(handle);
+}
+
+#endif